1. Field of the Invention
An aspect of this disclosure relates to a spectral characteristic measuring device and an image forming apparatus including the spectral characteristic measuring device.
2. Description of the Related Art
There is a demand for full-color, electrophotographic/inkjet image forming apparatuses (e.g., printers and copiers) that can print high-quality color images on recording media such as paper. Accordingly, improving color reproducibility is one of the most important technical goals. To achieve such a technical goal, for example, spectral characteristic measuring devices including an array of spectral sensors have been proposed.
For example, Japanese Laid-Open Patent Publication No. 2008-256594 discloses a spectral characteristic measuring device including an array of spectral sensors. In the spectral characteristic measuring device, components such as lenses, apertures, and diffraction gratings are arranged one- or two-dimensionally on plural glass substrates and the glass substrates are joined at appropriate intervals to form a spectral sensor array.
With the configuration of the related-art spectral characteristic measuring device, however, the apertures of optical systems of the spectral sensor array cannot be made greater than the array pitch of the spectral sensors and as a result, diffraction images obtained by the spectral sensors become relatively dark. This in turn makes it necessary to provide relatively-long exposure time to achieve desired accuracy and therefore makes it difficult to measure spectral characteristics at high speed.